/**
 * Copyright (C) 2004-2011 Jive Software. All rights reserved.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package xysoft.im.utils;



/**
 * Used to encrypt and decrypt bytes -- string using Base64 encoding and decoding.
 */
public class Base64 {

/* ********  P U B L I C   F I E L D S  ******** */


    /**
     * No options specified. Value is zero.
     */
    public final static int NO_OPTIONS = 0;

    /**
     * Specify encoding.
     */
    public final static int ENCODE = 1;


    /**
     * Specify decoding.
     */
    public final static int DECODE = 0;


    /**
     * Specify that data should be gzip-compressed.
     */
    public final static int GZIP = 2;


    /**
     * Don't break lines when encoding (violates strict Base64 specification)
     */
    public final static int DONT_BREAK_LINES = 8;

/* ********  P R I V A T E   F I E L D S  ******** */


    /**
     * Maximum line length (76) of Base64 output.
     */
    private final static int MAX_LINE_LENGTH = 76;


    /**
     * The equals sign (=) as a byte.
     */
    private final static byte EQUALS_SIGN = (byte)'=';


    /**
     * The new line character (\n) as a byte.
     */
    private final static byte NEW_LINE = (byte)'\n';


    /**
     * Preferred encoding.
     */
    private final static String PREFERRED_ENCODING = "UTF-8";


    /**
     * The 64 valid Base64 values.
     */
    private final static byte[] ALPHABET;
    private final static byte[] _NATIVE_ALPHABET = /* May be something funny like EBCDIC */
            {
                    (byte)'A', (byte)'B', (byte)'C', (byte)'D', (byte)'E', (byte)'F', (byte)'G',
                    (byte)'H', (byte)'I', (byte)'J', (byte)'K', (byte)'L', (byte)'M', (byte)'N',
                    (byte)'O', (byte)'P', (byte)'Q', (byte)'R', (byte)'S', (byte)'T', (byte)'U',
                    (byte)'V', (byte)'W', (byte)'X', (byte)'Y', (byte)'Z',
                    (byte)'a', (byte)'b', (byte)'c', (byte)'d', (byte)'e', (byte)'f', (byte)'g',
                    (byte)'h', (byte)'i', (byte)'j', (byte)'k', (byte)'l', (byte)'m', (byte)'n',
                    (byte)'o', (byte)'p', (byte)'q', (byte)'r', (byte)'s', (byte)'t', (byte)'u',
                    (byte)'v', (byte)'w', (byte)'x', (byte)'y', (byte)'z',
                    (byte)'0', (byte)'1', (byte)'2', (byte)'3', (byte)'4', (byte)'5',
                    (byte)'6', (byte)'7', (byte)'8', (byte)'9', (byte)'+', (byte)'/'
            };

    /** Determine which ALPHABET to use. */
    static {
        byte[] __bytes;
        try {
            __bytes = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/".getBytes(PREFERRED_ENCODING);
        }   // end try
        catch (java.io.UnsupportedEncodingException use) {
            __bytes = _NATIVE_ALPHABET; // Fall back to native encoding
        }   // end catch
        ALPHABET = __bytes;
    }   // end static


    /**
     * Translates a Base64 value to either its 6-bit reconstruction value
     * or a negative number indicating some other meaning.
     */
    private final static byte[] DECODABET =
            {
                    -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal  0 -  8
                    -5, -5, // Whitespace: Tab and Linefeed
                    -9, -9, // Decimal 11 - 12
                    -5, // Whitespace: Carriage Return
                    -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 14 - 26
                    -9, -9, -9, -9, -9, // Decimal 27 - 31
                    -5, // Whitespace: Space
                    -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 33 - 42
                    62, // Plus sign at decimal 43
                    -9, -9, -9, // Decimal 44 - 46
                    63, // Slash at decimal 47
                    52, 53, 54, 55, 56, 57, 58, 59, 60, 61, // Numbers zero through nine
                    -9, -9, -9, // Decimal 58 - 60
                    -1, // Equals sign at decimal 61
                    -9, -9, -9, // Decimal 62 - 64
                    0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, // Letters 'A' through 'N'
                    14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, // Letters 'O' through 'Z'
                    -9, -9, -9, -9, -9, -9, // Decimal 91 - 96
                    26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, // Letters 'a' through 'm'
                    39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, // Letters 'n' through 'z'
                    -9, -9, -9, -9                                 // Decimal 123 - 126
                    /*,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,     // Decimal 127 - 139
      -9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,     // Decimal 140 - 152
      -9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,     // Decimal 153 - 165
      -9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,     // Decimal 166 - 178
      -9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,     // Decimal 179 - 191
      -9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,     // Decimal 192 - 204
      -9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,     // Decimal 205 - 217
      -9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,     // Decimal 218 - 230
      -9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,     // Decimal 231 - 243
      -9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9         // Decimal 244 - 255 */
            };

    private final static byte WHITE_SPACE_ENC = -5; // Indicates white space in encoding
    private final static byte EQUALS_SIGN_ENC = -1; // Indicates equals sign in encoding


    /**
     * Defeats instantiation.
     */
    private Base64() {
    }

/* ********  E N C O D I N G   M E T H O D S  ******** */
    
    /**
     * Encodes up to the first three bytes of array <var>threeBytes</var>
     * and returns a four-byte array in Base64 notation.
     * The actual number of significant bytes in your array is
     * given by <var>numSigBytes</var>.
     * The array <var>threeBytes</var> needs only be as big as
     * <var>numSigBytes</var>.
     * Code can reuse a byte array by passing a four-byte array as <var>b4</var>.
     *
     * @param b4          A reusable byte array to reduce array instantiation
     * @param threeBytes  the array to convert
     * @param numSigBytes the number of significant bytes in your array
     * @return four byte array in Base64 notation.
     * @since 1.5.1
     */
    private static byte[] encode3to4(byte[] b4, byte[] threeBytes, int numSigBytes) {
        encode3to4(threeBytes, 0, numSigBytes, b4, 0);
        return b4;
    }   // end encode3to4


    /**
     * Encodes up to three bytes of the array <var>source</var>
     * and writes the resulting four Base64 bytes to <var>destination</var>.
     * The source and destination arrays can be manipulated
     * anywhere along their length by specifying
     * <var>srcOffset</var> and <var>destOffset</var>.
     * This method does not check to make sure your arrays
     * are large enough to accomodate <var>srcOffset</var> + 3 for
     * the <var>source</var> array or <var>destOffset</var> + 4 for
     * the <var>destination</var> array.
     * The actual number of significant bytes in your array is
     * given by <var>numSigBytes</var>.
     *
     * @param source      the array to convert
     * @param srcOffset   the index where conversion begins
     * @param numSigBytes the number of significant bytes in your array
     * @param destination the array to hold the conversion
     * @param destOffset  the index where output will be put
     * @return the <var>destination</var> array
     * @since 1.3
     */
    private static byte[] encode3to4(byte[] source, int srcOffset, int numSigBytes,
                                     byte[] destination, int destOffset) {
        //           1         2         3
        // 01234567890123456789012345678901 Bit position
        // --------000000001111111122222222 Array position from threeBytes
        // --------|    ||    ||    ||    | Six bit groups to index ALPHABET
        //          >>18  >>12  >> 6  >> 0  Right shift necessary
        //                0x3f  0x3f  0x3f  Additional AND

        // Create buffer with zero-padding if there are only one or two
        // significant bytes passed in the array.
        // We have to shift left 24 in order to flush out the 1's that appear
        // when Java treats a value as negative that is cast from a byte to an int.
        int inBuff = (numSigBytes > 0 ? ((source[srcOffset] << 24) >>> 8) : 0)
                | (numSigBytes > 1 ? ((source[srcOffset + 1] << 24) >>> 16) : 0)
                | (numSigBytes > 2 ? ((source[srcOffset + 2] << 24) >>> 24) : 0);

        switch (numSigBytes) {
            case 3:
                destination[destOffset] = ALPHABET[(inBuff >>> 18)];
                destination[destOffset + 1] = ALPHABET[(inBuff >>> 12) & 0x3f];
                destination[destOffset + 2] = ALPHABET[(inBuff >>> 6) & 0x3f];
                destination[destOffset + 3] = ALPHABET[(inBuff) & 0x3f];
                return destination;

            case 2:
                destination[destOffset] = ALPHABET[(inBuff >>> 18)];
                destination[destOffset + 1] = ALPHABET[(inBuff >>> 12) & 0x3f];
                destination[destOffset + 2] = ALPHABET[(inBuff >>> 6) & 0x3f];
                destination[destOffset + 3] = EQUALS_SIGN;
                return destination;

            case 1:
                destination[destOffset] = ALPHABET[(inBuff >>> 18)];
                destination[destOffset + 1] = ALPHABET[(inBuff >>> 12) & 0x3f];
                destination[destOffset + 2] = EQUALS_SIGN;
                destination[destOffset + 3] = EQUALS_SIGN;
                return destination;

            default:
                return destination;
        }   // end switch
    }   // end encode3to4


    /**
     * Serializes an object and returns the Base64-encoded
     * version of that serialized object. If the object
     * cannot be serialized or there is another error,
     * the method will return <tt>null</tt>.
     * The object is not GZip-compressed before being encoded.
     *
     * @param serializableObject The object to encode
     * @return The Base64-encoded object
     * @since 1.4
     */
    public static String encodeObject(java.io.Serializable serializableObject) {
        return encodeObject(serializableObject, NO_OPTIONS);
    }   // end encodeObject


    /**
     * Serializes an object and returns the Base64-encoded
     * version of that serialized object. If the object
     * cannot be serialized or there is another error,
     * the method will return <tt>null</tt>.
     * <p/>
     * Valid options:<pre>
     *   GZIP: gzip-compresses object before encoding it.
     *   DONT_BREAK_LINES: don't break lines at 76 characters
     *     <i>Note: Technically, this makes your encoding non-compliant.</i>
     * </pre>
     * <p/>
     * Example: <code>encodeObject( myObj, Base64.GZIP )</code> or
     * <p/>
     * Example: <code>encodeObject( myObj, Base64.GZIP | Base64.DONT_BREAK_LINES )</code>
     *
     * @param serializableObject The object to encode
     * @param options Options to encoding.
     * @return The Base64-encoded object
     * @see Base64#GZIP
     * @see Base64#DONT_BREAK_LINES
     * @since 2.0
     */
    public static String encodeObject(java.io.Serializable serializableObject, int options) {
        // Streams
        java.io.ByteArrayOutputStream baos = null;
        java.io.OutputStream b64os = null;
        java.io.ObjectOutputStream oos = null;
        java.util.zip.GZIPOutputStream gzos = null;

        // Isolate options
        int gzip = (options & GZIP);
        int dontBreakLines = (options & DONT_BREAK_LINES);

        try {
            // ObjectOutputStream -> (GZIP) -> Base64 -> ByteArrayOutputStream
            baos = new java.io.ByteArrayOutputStream();
            b64os = new Base64.OutputStream(baos, ENCODE | dontBreakLines);

            // GZip?
            if (gzip == GZIP) {
                gzos = new java.util.zip.GZIPOutputStream(b64os);
                oos = new java.io.ObjectOutputStream(gzos);
            }   // end if: gzip
            else
                oos = new java.io.ObjectOutputStream(b64os);

            oos.writeObject(serializableObject);
        }   // end try
        catch (java.io.IOException e) {
            //Log.error(e);
            return null;
        }   // end catch
        finally {
            try {
                oos.close();
            }
            catch (Exception e) {
                // Nothing to do
            }
            try {
                gzos.close();
            }
            catch (Exception e) {
                // Nothing to do
            }
            try {
                b64os.close();
            }
            catch (Exception e) {
                // Nothing to do
            }
            try {
                baos.close();
            }
            catch (Exception e) {
                // Nothing to do
            }
        }   // end finally

        // Return value according to relevant encoding.
        try {
            return new String(baos.toByteArray(), PREFERRED_ENCODING);
        }   // end try
        catch (java.io.UnsupportedEncodingException uue) {
            return new String(baos.toByteArray());
        }   // end catch

    }   // end encode


    /**
     * Encodes a byte array into Base64 notation.
     * Does not GZip-compress data.
     *
     * @param source The data to convert
     * @since 1.4
     * @return Encoded string.
     */
    public static String encodeBytes(byte[] source) {
        return encodeBytes(source, 0, source.length, NO_OPTIONS);
    }   // end encodeBytes


    /**
     * Encodes a byte array into Base64 notation.
     * <p/>
     * Valid options:<pre>
     *   GZIP: gzip-compresses object before encoding it.
     *   DONT_BREAK_LINES: don't break lines at 76 characters
     *     <i>Note: Technically, this makes your encoding non-compliant.</i>
     * </pre>
     * <p/>
     * Example: <code>encodeBytes( myData, Base64.GZIP )</code> or
     * <p/>
     * Example: <code>encodeBytes( myData, Base64.GZIP | Base64.DONT_BREAK_LINES )</code>
     *
     * @param source  The data to convert
     * @param options Specified options
     * @see Base64#GZIP
     * @see Base64#DONT_BREAK_LINES
     * @since 2.0
     * @return Encoded string.
     */
    public static String encodeBytes(byte[] source, int options) {
        return encodeBytes(source, 0, source.length, options);
    }   // end encodeBytes


    /**
     * Encodes a byte array into Base64 notation.
     * Does not GZip-compress data.
     *
     * @param source The data to convert
     * @param off    Offset in array where conversion should begin
     * @param len    Length of data to convert
     * @since 1.4
     * @return Encoded string.
     */
    public static String encodeBytes(byte[] source, int off, int len) {
        return encodeBytes(source, off, len, NO_OPTIONS);
    }   // end encodeBytes


    /**
     * Encodes a byte array into Base64 notation.
     * <p/>
     * Valid options:<pre>
     *   GZIP: gzip-compresses object before encoding it.
     *   DONT_BREAK_LINES: don't break lines at 76 characters
     *     <i>Note: Technically, this makes your encoding non-compliant.</i>
     * </pre>
     * <p/>
     * Example: <code>encodeBytes( myData, Base64.GZIP )</code> or
     * <p/>
     * Example: <code>encodeBytes( myData, Base64.GZIP | Base64.DONT_BREAK_LINES )</code>
     *
     * @param source  The data to convert
     * @param off     Offset in array where conversion should begin
     * @param len     Length of data to convert
     * @param options Specified options
     * @see Base64#GZIP
     * @see Base64#DONT_BREAK_LINES
     * @since 2.0
     * @return String that was encoded.
     */
    public static String encodeBytes(byte[] source, int off, int len, int options) {
        // Isolate options
        int dontBreakLines = (options & DONT_BREAK_LINES);
        int gzip = (options & GZIP);

        // Compress?
        if (gzip == GZIP) {
            java.io.ByteArrayOutputStream baos = null;
            java.util.zip.GZIPOutputStream gzos = null;
            Base64.OutputStream b64os = null;


            try {
                // GZip -> Base64 -> ByteArray
                baos = new java.io.ByteArrayOutputStream();
                b64os = new Base64.OutputStream(baos, ENCODE | dontBreakLines);
                gzos = new java.util.zip.GZIPOutputStream(b64os);

                gzos.write(source, off, len);
                gzos.close();
            }   // end try
            catch (java.io.IOException e) {
                //Log.error(e);
                return null;
            }   // end catch
            finally {
                try {
                    gzos.close();
                }
                catch (Exception e) {
                    // Nothing to do
                }
                try {
                    b64os.close();
                }
                catch (Exception e) {
                    // Nothing to do
                }
                try {
                    baos.close();
                }
                catch (Exception e) {
                    // Nothing to do
                }
            }   // end finally

            // Return value according to relevant encoding.
            try {
                return new String(baos.toByteArray(), PREFERRED_ENCODING);
            }   // end try
            catch (java.io.UnsupportedEncodingException uue) {
                return new String(baos.toByteArray());
            }   // end catch
        }   // end if: compress

        // Else, don't compress. Better not to use streams at all then.
        else {
            // Convert option to boolean in way that code likes it.
            boolean breakLines = dontBreakLines == 0;

            int len43 = len * 4 / 3;
            byte[] outBuff = new byte[(len43)                      // Main 4:3
                    + ((len % 3) > 0 ? 4 : 0)      // Account for padding
                    + (breakLines ? (len43 / MAX_LINE_LENGTH) : 0)]; // New lines
            int d = 0;
            int e = 0;
            int len2 = len - 2;
            int lineLength = 0;
            for (; d < len2; d += 3, e += 4) {
                encode3to4(source, d + off, 3, outBuff, e);

                lineLength += 4;
                if (breakLines && lineLength == MAX_LINE_LENGTH) {
                    outBuff[e + 4] = NEW_LINE;
                    e++;
                    lineLength = 0;
                }   // end if: end of line
            }   // en dfor: each piece of array

            if (d < len) {
                encode3to4(source, d + off, len - d, outBuff, e);
                e += 4;
            }   // end if: some padding needed

            // Return value according to relevant encoding.
            try {
                return new String(outBuff, 0, e, PREFERRED_ENCODING);
            }   // end try
            catch (java.io.UnsupportedEncodingException uue) {
                return new String(outBuff, 0, e);
            }   // end catch

        }   // end else: don't compress

    }   // end encodeBytes

/* ********  D E C O D I N G   M E T H O D S  ******** */


    /**
     * Decodes four bytes from array <var>source</var>
     * and writes the resulting bytes (up to three of them)
     * to <var>destination</var>.
     * The source and destination arrays can be manipulated
     * anywhere along their length by specifying
     * <var>srcOffset</var> and <var>destOffset</var>.
     * This method does not check to make sure your arrays
     * are large enough to accomodate <var>srcOffset</var> + 4 for
     * the <var>source</var> array or <var>destOffset</var> + 3 for
     * the <var>destination</var> array.
     * This method returns the actual number of bytes that
     * were converted from the Base64 encoding.
     *
     * @param source      the array to convert
     * @param srcOffset   the index where conversion begins
     * @param destination the array to hold the conversion
     * @param destOffset  the index where output will be put
     * @return the number of decoded bytes converted
     * @since 1.3
     */
    private static int decode4to3(byte[] source, int srcOffset, byte[] destination, int destOffset) {
        // Example: Dk==
        if (source[srcOffset + 2] == EQUALS_SIGN) {
            // Two ways to do the same thing. Don't know which way I like best.
            //int outBuff =   ( ( DECODABET[ source[ srcOffset    ] ] << 24 ) >>>  6 )
            //              | ( ( DECODABET[ source[ srcOffset + 1] ] << 24 ) >>> 12 );
            int outBuff = ((DECODABET[source[srcOffset]] & 0xFF) << 18)
                    | ((DECODABET[source[srcOffset + 1]] & 0xFF) << 12);

            destination[destOffset] = (byte)(outBuff >>> 16);
            return 1;
        }

        // Example: DkL=
        else if (source[srcOffset + 3] == EQUALS_SIGN) {
            // Two ways to do the same thing. Don't know which way I like best.
            //int outBuff =   ( ( DECODABET[ source[ srcOffset     ] ] << 24 ) >>>  6 )
            //              | ( ( DECODABET[ source[ srcOffset + 1 ] ] << 24 ) >>> 12 )
            //              | ( ( DECODABET[ source[ srcOffset + 2 ] ] << 24 ) >>> 18 );
            int outBuff = ((DECODABET[source[srcOffset]] & 0xFF) << 18)
                    | ((DECODABET[source[srcOffset + 1]] & 0xFF) << 12)
                    | ((DECODABET[source[srcOffset + 2]] & 0xFF) << 6);

            destination[destOffset] = (byte)(outBuff >>> 16);
            destination[destOffset + 1] = (byte)(outBuff >>> 8);
            return 2;
        }

        // Example: DkLE
        else {
            try {
                // Two ways to do the same thing. Don't know which way I like best.
                //int outBuff =   ( ( DECODABET[ source[ srcOffset     ] ] << 24 ) >>>  6 )
                //              | ( ( DECODABET[ source[ srcOffset + 1 ] ] << 24 ) >>> 12 )
                //              | ( ( DECODABET[ source[ srcOffset + 2 ] ] << 24 ) >>> 18 )
                //              | ( ( DECODABET[ source[ srcOffset + 3 ] ] << 24 ) >>> 24 );
                int outBuff = ((DECODABET[source[srcOffset]] & 0xFF) << 18)
                        | ((DECODABET[source[srcOffset + 1]] & 0xFF) << 12)
                        | ((DECODABET[source[srcOffset + 2]] & 0xFF) << 6)
                        | ((DECODABET[source[srcOffset + 3]] & 0xFF));


                destination[destOffset] = (byte)(outBuff >> 16);
                destination[destOffset + 1] = (byte)(outBuff >> 8);
                destination[destOffset + 2] = (byte)(outBuff);

                return 3;
            }
            catch (Exception e) {
//                Log.error("" + source[srcOffset] + ": " + (DECODABET[source[srcOffset]]));
//                Log.error("" + source[srcOffset + 1] + ": " + (DECODABET[source[srcOffset + 1]]));
//                Log.error("" + source[srcOffset + 2] + ": " + (DECODABET[source[srcOffset + 2]]));
//                Log.error("" + source[srcOffset + 3] + ": " + (DECODABET[source[srcOffset + 3]]));
                return -1;
            }   //e nd catch
        }
    }   // end decodeToBytes


    /**
     * Very low-level access to decoding ASCII characters in
     * the form of a byte array. Does not support automatically
     * gunzipping or any other "fancy" features.
     *
     * @param source The Base64 encoded data
     * @param off    The offset of where to begin decoding
     * @param len    The length of characters to decode
     * @return decoded data
     * @since 1.3
     */
    public static byte[] decode(byte[] source, int off, int len) {
        int len34 = len * 3 / 4;
        byte[] outBuff = new byte[len34]; // Upper limit on size of output
        int outBuffPosn = 0;

        byte[] b4 = new byte[4];
        int b4Posn = 0;
        int i;
        byte sbiCrop;
        byte sbiDecode;
        for (i = off; i < off + len; i++) {
            sbiCrop = (byte)(source[i] & 0x7f); // Only the low seven bits
            sbiDecode = DECODABET[sbiCrop];

            if (sbiDecode >= WHITE_SPACE_ENC) // White space, Equals sign or better
            {
                if (sbiDecode >= EQUALS_SIGN_ENC) {
                    b4[b4Posn++] = sbiCrop;
                    if (b4Posn > 3) {
                        outBuffPosn += decode4to3(b4, 0, outBuff, outBuffPosn);
                        b4Posn = 0;

                        // If that was the equals sign, break out of 'for' loop
                        if (sbiCrop == EQUALS_SIGN)
                            break;
                    }   // end if: quartet built

                }   // end if: equals sign or better

            }   // end if: white space, equals sign or better
            else {
                System.err.println("Bad Base64 input character at " + i + ": " + source[i] + "(decimal)");
                return null;
            }   // end else:
        }   // each input character

        byte[] out = new byte[outBuffPosn];
        System.arraycopy(outBuff, 0, out, 0, outBuffPosn);
        return out;
    }   // end decode


    /**
     * Decodes data from Base64 notation, automatically
     * detecting gzip-compressed data and decompressing it.
     *
     * @param s the string to decode
     * @return the decoded data
     * @since 1.4
     */
    public static byte[] decode(String s) {
        byte[] bytes;
        try {
            bytes = s.getBytes(PREFERRED_ENCODING);
        }   // end try
        catch (java.io.UnsupportedEncodingException uee) {
            bytes = s.getBytes();
        }   // end catch
        //</change>

        // Decode
        bytes = decode(bytes, 0, bytes.length);

        // Check to see if it's gzip-compressed
        // GZIP Magic Two-Byte Number: 0x8b1f (35615)
        if (bytes.length >= 2) {

            int head = ((int)bytes[0] & 0xff) | ((bytes[1] << 8) & 0xff00);
            if (
                    bytes != null && // In case decoding returned null
                            bytes.length >= 4 && // Don't want to get ArrayIndexOutOfBounds exception
                            java.util.zip.GZIPInputStream.GZIP_MAGIC == head) {
                java.io.ByteArrayInputStream bais = null;
                java.util.zip.GZIPInputStream gzis = null;
                java.io.ByteArrayOutputStream baos = null;
                byte[] buffer = new byte[2048];
                int length;

                try {
                    baos = new java.io.ByteArrayOutputStream();
                    bais = new java.io.ByteArrayInputStream(bytes);
                    gzis = new java.util.zip.GZIPInputStream(bais);

                    while ((length = gzis.read(buffer)) >= 0) {
                        baos.write(buffer, 0, length);
                    }   // end while: reading input

                    // No error? Get new bytes.
                    bytes = baos.toByteArray();

                }   // end try
                catch (java.io.IOException e) {
                    // Just return originally-decoded bytes
                }   // end catch
                finally {
                    try {
                        baos.close();
                    }
                    catch (Exception e) {
                        // Nothing to do
                    }
                    try {
                        gzis.close();
                    }
                    catch (Exception e) {
                        // Nothing to do
                    }
                    try {
                        bais.close();
                    }
                    catch (Exception e) {
                        // Nothing to do
                    }
                }   // end finally

            }   // end if: gzipped
        }   // end if: bytes.length >= 2

        return bytes;
    }   // end decode


    /**
     * Attempts to decode Base64 data and deserialize a Java
     * Object within. Returns <tt>null</tt> if there was an error.
     *
     * @param encodedObject The Base64 data to decode
     * @return The decoded and deserialized object
     * @since 1.5
     */
    public static Object decodeToObject(String encodedObject) {
        // Decode and gunzip if necessary
        byte[] objBytes = decode(encodedObject);

        java.io.ByteArrayInputStream bais = null;
        java.io.ObjectInputStream ois = null;
        Object obj = null;

        try {
            bais = new java.io.ByteArrayInputStream(objBytes);
            ois = new java.io.ObjectInputStream(bais);

            obj = ois.readObject();
        }   // end try
        catch (java.io.IOException e) {
            //Log.error(e);
            obj = null;
        }   // end catch
        catch (java.lang.ClassNotFoundException e) {
            //Log.error(e);
            obj = null;
        }   // end catch
        finally {
            try {
                if (bais != null)
                    bais.close();
            }
            catch (Exception e) {
                // Nothing to do
            }
            try {
                if (ois != null)
                    ois.close();
            }
            catch (Exception e) {
                // Nothing to do
            }
        }   // end finally

        return obj;
    }   // end decodeObject

    /* ********  I N N E R   C L A S S   I N P U T S T R E A M  ******** */


    /**
     * A InputStream will read data from another
     * {@link java.io.InputStream}, given in the constructor,
     * and encode/decode to/from Base64 notation on the fly.
     *
     * @see Base64
     * @see java.io.FilterInputStream
     * @since 1.3
     */
    public static class InputStream extends java.io.FilterInputStream {
        private boolean encode;         // Encoding or decoding
        private int position;       // Current position in the buffer
        private byte[] buffer;         // Small buffer holding converted data
        private int bufferLength;   // Length of buffer (3 or 4)
        private int numSigBytes;    // Number of meaningful bytes in the buffer
        private int lineLength;
        private boolean breakLines;     // Break lines at less than 80 characters


        /**
         * Constructs a InputStream in DECODE mode.
         *
         * @param in the {@link java.io.InputStream} from which to read data.
         * @since 1.3
         */
        public InputStream(java.io.InputStream in) {
            this(in, DECODE);
        }   // end constructor


        /**
         * Constructs a InputStream in
         * either ENCODE or DECODE mode.
         * <p/>
         * Valid options:<pre>
         *   ENCODE or DECODE: Encode or Decode as data is read.
         *   DONT_BREAK_LINES: don't break lines at 76 characters
         *     (only meaningful when encoding)
         *     <i>Note: Technically, this makes your encoding non-compliant.</i>
         * </pre>
         * <p/>
         * Example: <code>new Base64.InputStream( in, Base64.DECODE )</code>
         *
         * @param in      the {@link java.io.InputStream} from which to read data.
         * @param options Specified options
         * @see Base64#ENCODE
         * @see Base64#DECODE
         * @see Base64#DONT_BREAK_LINES
         * @since 2.0
         */
        public InputStream(java.io.InputStream in, int options) {
            super(in);
            this.breakLines = (options & DONT_BREAK_LINES) != DONT_BREAK_LINES;
            this.encode = (options & ENCODE) == ENCODE;
            this.bufferLength = encode ? 4 : 3;
            this.buffer = new byte[bufferLength];
            this.position = -1;
            this.lineLength = 0;
        }   // end constructor

        /**
         * Reads enough of the input stream to convert
         * to/from Base64 and returns the next byte.
         *
         * @return next byte
         * @since 1.3
         */
        public int read() throws java.io.IOException {
            // Do we need to get data?
            if (position < 0) {
                if (encode) {
                    byte[] b3 = new byte[3];
                    int numBinaryBytes = 0;
                    for (int i = 0; i < 3; i++) {
                        try {
                            int b = in.read();

                            // If end of stream, b is -1.
                            if (b >= 0) {
                                b3[i] = (byte)b;
                                numBinaryBytes++;
                            }   // end if: not end of stream

                        }   // end try: read
                        catch (java.io.IOException e) {
                            // Only a problem if we got no data at all.
                            if (i == 0)
                                throw e;

                        }   // end catch
                    }   // end for: each needed input byte

                    if (numBinaryBytes > 0) {
                        encode3to4(b3, 0, numBinaryBytes, buffer, 0);
                        position = 0;
                        numSigBytes = 4;
                    }   // end if: got data
                    else {
                        return -1;
                    }   // end else
                }   // end if: encoding

                // Else decoding
                else {
                    byte[] b4 = new byte[4];
                    int i;
                    for (i = 0; i < 4; i++) {
                        // Read four "meaningful" bytes:
                        int b;
                        do {
                            b = in.read();
                        }
                        while (b >= 0 && DECODABET[b & 0x7f] <= WHITE_SPACE_ENC);

                        if (b < 0)
                            break; // Reads a -1 if end of stream

                        b4[i] = (byte)b;
                    }   // end for: each needed input byte

                    if (i == 4) {
                        numSigBytes = decode4to3(b4, 0, buffer, 0);
                        position = 0;
                    }   // end if: got four characters
                    else if (i == 0) {
                        return -1;
                    }   // end else if: also padded correctly
                    else {
                        // Must have broken out from above.
                        throw new java.io.IOException("Improperly padded Base64 input.");
                    }   // end

                }   // end else: decode
            }   // end else: get data

            // Got data?
            if (position >= 0) {
                // End of relevant data?
                if (/*!encode &&*/ position >= numSigBytes)
                    return -1;

                if (encode && breakLines && lineLength >= MAX_LINE_LENGTH) {
                    lineLength = 0;
                    return '\n';
                }   // end if
                else {
                    lineLength++;   // This isn't important when decoding
                    // but throwing an extra "if" seems
                    // just as wasteful.

                    int b = buffer[position++];

                    if (position >= bufferLength)
                        position = -1;

                    return b & 0xFF; // This is how you "cast" a byte that's
                    // intended to be unsigned.
                }   // end else
            }   // end if: position >= 0

            // Else error
            else {
                // When JDK1.4 is more accepted, use an assertion here.
                throw new java.io.IOException("Error in Base64 code reading stream.");
            }   // end else
        }   // end read


        /**
         * Calls {@link #read} repeatedly until the end of stream
         * is reached or <var>len</var> bytes are read.
         * Returns number of bytes read into array or -1 if
         * end of stream is encountered.
         *
         * @param dest array to hold values
         * @param off  offset for array
         * @param len  max number of bytes to read into array
         * @return bytes read into array or -1 if end of stream is encountered.
         * @since 1.3
         */
        public int read(byte[] dest, int off, int len) throws java.io.IOException {
            int i;
            int b;
            for (i = 0; i < len; i++) {
                b = read();

                //if( b < 0 && i == 0 )
                //    return -1;

                if (b >= 0)
                    dest[off + i] = (byte)b;
                else if (i == 0)
                    return -1;
                else
                    break; // Out of 'for' loop
            }   // end for: each byte read
            return i;
        }   // end read

    }   // end inner class InputStream

    /* ********  I N N E R   C L A S S   O U T P U T S T R E A M  ******** */


    /**
     * A outputStream will write data to another
     * {@link java.io.OutputStream}, given in the constructor,
     * and encode/decode to/from Base64 notation on the fly.
     *
     * @see Base64
     * @see java.io.FilterOutputStream
     * @since 1.3
     */
    public static class OutputStream extends java.io.FilterOutputStream {
        private boolean encode;
        private int position;
        private byte[] buffer;
        private int bufferLength;
        private int lineLength;
        private boolean breakLines;
        private byte[] b4; // Scratch used in a few places
        private boolean suspendEncoding;

        /**
         * Constructs a OutputStream in ENCODE mode.
         *
         * @param out the {@link java.io.OutputStream} to which data will be written.
         * @since 1.3
         */
        public OutputStream(java.io.OutputStream out) {
            this(out, ENCODE);
        }   // end constructor


        /**
         * Constructs a OutputStream in
         * either ENCODE or DECODE mode.
         * <p/>
         * Valid options:<pre>
         *   ENCODE or DECODE: Encode or Decode as data is read.
         *   DONT_BREAK_LINES: don't break lines at 76 characters
         *     (only meaningful when encoding)
         *     <i>Note: Technically, this makes your encoding non-compliant.</i>
         * </pre>
         * <p/>
         * Example: <code>new Base64.OutputStream( out, Base64.ENCODE )</code>
         *
         * @param out     the {@link java.io.OutputStream} to which data will be written.
         * @param options Specified options.
         * @see Base64#ENCODE
         * @see Base64#DECODE
         * @see Base64#DONT_BREAK_LINES
         * @since 1.3
         */
        public OutputStream(java.io.OutputStream out, int options) {
            super(out);
            this.breakLines = (options & DONT_BREAK_LINES) != DONT_BREAK_LINES;
            this.encode = (options & ENCODE) == ENCODE;
            this.bufferLength = encode ? 3 : 4;
            this.buffer = new byte[bufferLength];
            this.position = 0;
            this.lineLength = 0;
            this.suspendEncoding = false;
            this.b4 = new byte[4];
        }   // end constructor


        /**
         * Writes the byte to the output stream after
         * converting to/from Base64 notation.
         * When encoding, bytes are buffered three
         * at a time before the output stream actually
         * gets a write() call.
         * When decoding, bytes are buffered four
         * at a time.
         *
         * @param theByte the byte to write
         * @since 1.3
         */
        public void write(int theByte) throws java.io.IOException {
            // Encoding suspended?
            if (suspendEncoding) {
                super.out.write(theByte);
                return;
            }   // end if: supsended

            // Encode?
            if (encode) {
                buffer[position++] = (byte)theByte;
                if (position >= bufferLength)  // Enough to encode.
                {
                    out.write(encode3to4(b4, buffer, bufferLength));

                    lineLength += 4;
                    if (breakLines && lineLength >= MAX_LINE_LENGTH) {
                        out.write(NEW_LINE);
                        lineLength = 0;
                    }   // end if: end of line

                    position = 0;
                }   // end if: enough to output
            }   // end if: encoding

            // Else, Decoding
            else {
                // Meaningful Base64 character?
                if (DECODABET[theByte & 0x7f] > WHITE_SPACE_ENC) {
                    buffer[position++] = (byte)theByte;
                    if (position >= bufferLength)  // Enough to output.
                    {
                        int len = Base64.decode4to3(buffer, 0, b4, 0);
                        out.write(b4, 0, len);
                        //out.write( Base64.decode4to3( buffer ) );
                        position = 0;
                    }   // end if: enough to output
                }   // end if: meaningful base64 character
                else if (DECODABET[theByte & 0x7f] != WHITE_SPACE_ENC) {
                    throw new java.io.IOException("Invalid character in Base64 data.");
                }   // end else: not white space either
            }   // end else: decoding
        }   // end write


        /**
         * Calls {@link #write} repeatedly until <var>len</var>
         * bytes are written.
         *
         * @param theBytes array from which to read bytes
         * @param off      offset for array
         * @param len      max number of bytes to read into array
         * @since 1.3
         */
        public void write(byte[] theBytes, int off, int len) throws java.io.IOException {
            // Encoding suspended?
            if (suspendEncoding) {
                super.out.write(theBytes, off, len);
                return;
            }   // end if: supsended

            for (int i = 0; i < len; i++) {
                write(theBytes[off + i]);
            }   // end for: each byte written

        }   // end write


        /**
         * Method added by PHIL. [Thanks, PHIL. -Rob]
         * This pads the buffer without closing the stream.
         *
         * @throws java.io.IOException if there's an error during flush.
         */
        public void flushBase64() throws java.io.IOException {
            if (position > 0) {
                if (encode) {
                    out.write(encode3to4(b4, buffer, position));
                    position = 0;
                }   // end if: encoding
                else {
                    throw new java.io.IOException("Base64 input not properly padded.");
                }   // end else: decoding
            }   // end if: buffer partially full

        }   // end flush


        /**
         * Flushes and closes (I think, in the superclass) the stream.
         *
         * @since 1.3
         */
        public void close() throws java.io.IOException {
            // 1. Ensure that pending characters are written
            flushBase64();

            // 2. Actually close the stream
            // Base class both flushes and closes.
            super.close();

            buffer = null;
            out = null;
        }   // end close


        /**
         * Suspends encoding of the stream.
         * May be helpful if you need to embed a piece of
         * base640-encoded data in a stream.
         *
         * @since 1.5.1
         * @throws java.io.IOException ie an error occurs during suspension.
         */
        public void suspendEncoding() throws java.io.IOException {
            flushBase64();
            this.suspendEncoding = true;
        }   // end suspendEncoding


        /**
         * Resumes encoding of the stream.
         * May be helpful if you need to embed a piece of
         * base640-encoded data in a stream.
         *
         * @since 1.5.1
         */
        public void resumeEncoding() {
            this.suspendEncoding = false;
        }   // end resumeEncoding


    }   // end inner class OutputStream


}   // end class Base64
